The present invention relates to a device for fixing an open position of a door of an automobile to be used in a painting operation by a robot, for example.
Generally, in a production line of automobiles, when each automobile placed on a carriage is stopped at a given painting position on the production line, a door of the automobile is opened by a robot.
Under the open condition of the door, a door open position fixing device 1 as shown in FIGS. 4A and 4B is used to fix an open position of the door. That is, a door 3 is fixed at its open position by a presser member 2 of the door open position fixing device 1. Thereafter, an inner surface of the door 3 and an inside of the automobile are painted by a painting robot.
More specifically, when a swing lever 6 is driven by a hydraulic cylinder 7 through a rack 4 and a pinion gear 5 to swing upwardly, the presser member 2 mounted at a free end of the swing lever 6 comes to abutment against the inner surface of the door 3 and presses the door 3 in an opening direction thereof, thereby maintaining the open condition of the door 3.
The abutment of the presser member 2 against the door 3 is detected by a proximity switch provided in the presser member
In general, an opening angle of the door 3 has a large variation (e.g., 0-100 mm on the side of an opening end of the door 3) due to an assembling error or the like even if the automobiles are of the same kind. Accordingly, the above door open position fixing device 1 is so designed as to urge each door of the automobiles by a relatively large pressing force in accordance with the door having a maximum opening angle (variation in opening angle).
In recent years, a system of assembling many kinds of automobiles on a single production line has been widely adopted in order to improve the efficiency of production. In the case of applying the above-mentioned door open position fixing device to the above system, as the doors of the automobiles of different kinds have different opening angles and mounting structures, it is necessary to urge each door by a maximum pressing force in accordance with some kind of the automobile having a maximum door opening angle, so as to cover all the kinds of the doors and absorb the variation of the opening angle of each door.
However, if each door is urged by such a maximum pressing force to be required, there may arise a problem that some kinds of doors will be broken because all the doors of different kinds have different opening angles and mounting structures as mentioned above.